Mark the odd one in each series:
(a) Areolar tissue, blood, neuron, tendon
(b) RBC, WBC, platelets, cartilage
(c) Exocrine, endocrine, salivary gland, ligament
(d) Maxilla, mandible, labrum, antennae
(e) Protonema, mesothorax, metathorax, coxa

Solution: (a) Areolar tissue, blood, and tendons are examples of connective tissues. Neuron is an example of neural tissue.
(b) RBCs, WBCs, and platelets are the three most important components of blood. Cartilage is therefore, the odd one out.
(c) Exocrine, endocrine, and salivary glands are examples of simple glandular epithelium. Ligament is a connective tissue.
(d) Maxilla, mandible, and labrum are mouthparts of a cockroach. Antennae, on the other hand, are present in the head region of cockroaches.
(e) Protonema forms the developmental stage in the life cycle of a moss. Mesothorax, metathorax, and coxa are parts or segments present in the legs of a cockroach.